This commensal organism is part of the gastrointestinal tract flora and can become extremely virulent, often in the setting of immuno-suppression such as neutropenia, occult malignancy(commonly caecal) and poorly controlled diabetes.

• 这种（与人类）共生生物是胃肠道菌群的一部分，可以变得毒性巨大，通常发生于机体免疫受抑制，如中性粒细胞减少症，隐蔽的肿瘤（一般如盲肠），或者控制不佳的糖尿病。